The present invention generally relates to a process for making wrappers for smoking articles such as cigarettes, and more specifically to a process for making cigarette wrappers which modify the mass burn rate of the cigarette.
It is beneficial to make cigarettes in commercial quantities which will have a reduced burn rate if not drawn on by the smoker but which will look, feel, taste and burn like a conventional cigarette when being drawn on by the smoker at normal intervals. It is recognized by those skilled in the art that the wrapper construction of the cigarette strongly, influences these characteristics.
Cigarettes made to have a reduced burn rate through a modification of the wrapper have been described previously. For example, Weinert U.S. Pat. No. 4,489,650 describes a cigarette in which the interior surface of the wrapper is coated with clay. In Cohn U.S. Pat. No. 4,044,778, the cigarette wrapper includes rings or areas coated with an alkali silicate which renders the wrapper non-burning in the coated areas.
Durocher U.S. Pat. No. 4,615,345 describes a wrapper made of a cellulose fiber base which normally does not sustain burning when the wrapper is incorporated into a cigarette. The wrapper is treated in selected zones with an alkali metal burn promoter such as the potassium salt of citric acid. It is described that a cigarette made with a wrapper so treated will smolder without being drawn on by the smoker when in the treated zone but when the treated zone is consumed will extinguish itself unless the cigarette is drawn on by the smoker. Cigarette wrappers of the character described in Durocher have not been found to produce cigarettes which look, feel, taste and burn like a conventional cigarette.
Hampl U.S. Pat. No. 4,739,775 also describes a cigarette wrapper which will sustain burning only if drawn on by the smoker at normal intervals. Bands of a cellulose fiber base web which will not sustain burn are added to a conventional cigarette wrapper. The bands are selected and positioned to create a cigarette with the desired burning characteristics. While cigarette wrappers of the character described in Hampl have been found to exhibit the desired look, feel, taste and burn qualities, there was no known process for making such cigarette wrappers in commercial quantities.
Accordingly, it is the object of the present invention to provide a process for making wrappers in commercial quantities which produce cigarettes which will have a reduced burn rate if not drawn on by the smoker but which look, feel, taste and burn like a conventional cigarette when being drawn on by the smoker at normal intervals.
Another object of this invention is to provide a process for making wrappers in commercial quantities which produce cigarettes which exhibit the burning characteristics described in Hampl U.S. Pat. No. 4,739,775 or Durocher U.S. Pat. No. 4,615,345.
A further object of this invention is to provide a process for making wrappers which modify the mass burn rate of the cigarette by applying circumscribing bands of paper of specified width at intervals along the longitudinal axis of a cigarette wrapper. Both the bands of paper and the cigarette wrapper may be selected from conventional materials or specially selected or chemically treated materials so as to provide a cigarette with the desired mass burn rate.